April, 1910.] 



305 



Fibres. 



as would be expected, but remain quite 

 distinct, each one being coated with a 

 pellicle, which cements the fuzz closely 

 to the surface and thus allows the seeds 

 to separate freely from one another. 

 This method of treating the seed is not 

 only useful for enabling a separation 

 to be made of the heavy from the light 

 seed, but also facilitates sowing, as a 

 uniform number of seeds can be readily 

 dropped at regular distances, and thus 

 obviates the necessity for thinning out 

 the young plants. 



For separating the heavy seed, a 

 special form of air-blast fanning mill 

 is recommended. The seeds prepared in 

 the manner described are fed from a 

 hopper on to a vibrating screen, which 

 catches large wads of cotton or foreign 

 substances and discharges them, but 

 allows the cotton seed to pass through 

 its meshes to another vibrating screen, 

 with fine meshes. From this latter 

 screen the seeds are delivered into a 

 short flue, where they meet a current 

 of air driven by a fan from below, 

 which forces the light seeds out through 

 the top of the flue, but allows the 

 heavy ones to drop into a box below. 

 The separation, thus effected, does not 

 altogether correspond with the actual 

 weight or size of the seed, but depends 

 to some extent on its specific gravity, 

 but this is probably an advantage, as 

 the seeds of high specific gravity are 

 obviously more desirable than large 

 seeds, which have imperfectly developed 

 or withered kernels. 



Some experiments have been made 

 with cotton seeds which were separated 

 into heavy, medium, light, and very 

 light grades. A much larger proportion 

 of the heavy seeds germinated than of 

 the light seeds, but the latter germi- 

 nated more quickly. The^ plants from 

 the light seed appeared weak and un- 

 healthy, whilst those from the heavy 

 seed were strong and vigorous. 



A trial was made on about two aces 

 of land in South Carolina in which 

 heavy seeds and un«eparated seeds of 

 the same variety were planted in alter- 

 nate rows. The heavy seed yielded a 

 crop of 1,047^ lbs., and the unseparated 

 seed a crop of 944J lbs. In another trial 

 one acre was planted with heavy seed 

 and another with unseparated seed ; a 

 yield of 1,164^ lbs. was obtained from the 

 former, and 1,0755 lbs. from the latter. 

 Both these tests were carried out under 

 ordinary field conditions, and showed 

 that the crop is increased by about 10 

 per cent, by the use of heavy seed. 



The evidence so far obtained has 

 shown that this simple method _ of 

 separating the heavy seed for sowing 

 is not only likely to increase directly 

 39 



the profits of the cotton farmer, but 

 will probably also be found to check 

 deterioration and effect a general im- 

 provement in the varieties grown. 



METHOD OF ESTIMATING THE 

 YIELD OF COTTON IN THE FIELD. 



(From the Queensland Agricultural 

 Journal, Vol. XXII., Pt. 5, May, 1909.) 



To estimate the yield of cotton from 

 the plants in the field, the following 

 directions, says Mr. J. C. Crawford, 

 Special Agent, U.S. Bureau of Entomo- 

 logy, will be found useful : — 



Determine the average number of 

 sound bolls per plant by counting the 

 number of such bolls on some five ad- 

 jacent plants in at least three separate 

 places in the field, and dividing the total 

 number of bolls counted in this manner 

 by the total number of plants examined. 

 Where the field is very large or contains 

 different soils, more than three places 

 should be selected for counting. In the 

 first column of the following table find 

 the distance between the plants in the 

 field, the crop of which is to be esti- 

 mated. Then refer to the number on 

 the same line in the following column, 

 headed by the size of bolls to which the 

 variety planted belongs. Dividing the 

 average number of bolls per plant in the 

 field by the number found in this manner 

 in the table will give the fraction of a 

 bale per acre that will be produced. 



Example. — If, in the case of a small- 

 boll variety like the King, the average 

 number of bolls per plant is found to be 

 10, and the plants are put in at a distance 

 of 2 ft. in rows, 4 ft. apart, the amount 

 of the prospective yield per acre will be 

 10 divided by 25-4 or 0"39 of a bale. In 

 using this table, due allowance must be 

 made for a poor stand :— 



Number of Cotton Bolls per Plant 

 op Various Classes Required at 

 Certain Distances to Produce a 

 Bale per Acre when Cotton 

 gives 331 per crnt. op llnt, 



Distance be- 



Uumber of Lai!?o Bolls. 



Medium- 

 sized Bolls, 

 70 to 80 

 per lb. 



Small 

 Bolls, 85 

 to 100 

 per lb. 



ween Plants Plants per 

 in feet. acre. 



5C to 65 

 per lb. 



1 X 



3 



14,520 



5-9 



7-7 



9-5 



1 x 



4 



10,890 



7-9 



10-3 



127 



I X 



5 



8,712 



9-8 



129 



15-9 



1 x 



6 



7,260 



11-8 



15-4 



19 '1 



14 x 



3 



9,680 



8-9 



116 



140 



l|x 



4 



7,260 



11-8 



15-4 



19-1 



l|x 



5 



5,808 



14-8 



19-3 



23 8 



if x 



6 



4,840 



17-8 



23 2 



28-6 



2 x 



2 



10,890 



7-9 



103 



127 



2 x 



3 



7,260 



11-8 



15-4 



19-1 



2 x 



4 



5,445 



15-8 



20 6 



25-4 



2 x 



5 



4,356 



19-7 



25-8 



31-8 



2 x 



6 



3,630 



23-2 



30-9 



38 '4 



3 x 



3 



4,840 



17-8 



23-2 



28-6 



